This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. Section 119 from an application for xe2x80x9cMethod for Operating Supplemental Code Channel for High-Speed Data Service in Radio Telecommunication Systemxe2x80x9d filed in the Korean Industrial Property Office on Mar. 13, 1999 and there duly assigned Serial No. 99-8441.
1. Field of the Invention
The present invention relates generally to a method for providing a data service in a radio telecommunication system, and in particular, to a method for allocating and controlling a plurality of traffic channels between a base station and a mobile station to provide a high-speed data service to the mobile station using the CDMA (Code Division Multiple Access) technique.
2.Description of the Related Art
In order to provide the radio communication service to a greater number of subscribers, a cellular system divides the whole service area into a plurality of cells, each including a base station, and manages a plurality of the base stations using a private communication exchange (PCX).
In the advanced radio telecommunication system, an interworking function system (IWF) is connected to a radio network including the base station and the private communication exchange, and the radio network is connected to a wired network, such as a public switched telephone network (PSTN) and the Internet through the interworking function system, thereby providing the mobile subscriber with the data service, such as facsimile and Internet services.
FIGS. 1 and 2 illustrate the general network structure for providing data service to mobile subscribers in a CDMA system. As illustrated, a mobile subscriber accesses a mobile station (MS) 120 using a terminal end (TE) 110 such as a notebook computer, and the mobile station 120 is connected to a radio network including a base station/base station controller (BS/BSC) 130 and a private communication exchange (PCX) 140. The interworking function system (IWF) 150 connects the radio network to a wired network, such as a public switched telephone network (PSTN) 160 or Internet 180, to connect the terminal end 110 to a facsimile 170 or a personal computer (PC) 190.
The above network, the terminal end 110 can exchange the data with the facsimile 170 connected to the PSTN 160 and the personal computer 190 connected through Internet 180. Although the data rate is relatively lower compared to the wired data service, it is possible to provide some mobility and service to the terminal end 110.
The CDMA radio network, which separates one frequency channel into a plurality of code channels using codes, can support the greater number of subscribers compared to the frequency division multiple access (FDMA) radio network.
FIG. 3 shows the general structure of a reverse code channel (for transmitting signals from the mobile station to the base station) for a CDMA radio telecommunication system. As illustrated, the reverse channel 210 having a bandwidth of 1.23 MHz includes a plurality of access channels 211-214 each corresponding to one paging channel and a plurality of traffic channels 215-216 for transmitting the voice and the data information.
FIG. 4 shows the general structure of a forward code channel (for transmitting signals from the base station to the mobile station) for the CDMA radio telecommunication system. As illustrated, the forward channel 220 having a bandwidth of 1.23 MHz includes a pilot channel 221 for transmitting the unique base station signal, a sync channel 222 for transmitting a system time of the base station, a plurality of paging channels 223-224 each corresponding to one access channel, and a plurality of traffic code channels 225-229 for transmitting voice and data information. The forward traffic code channels 225-229 each transmit the traffic data 230, such as voice and data, and power control data 231, for controlling the power of the mobile station.
The TIA/EIA/IS-95 CDMA radio network only supports the data rate of 8.6 Kbps (Rate Set 1) or 13.35 Kbps (Rate Set 2) for each code channel. However, in order to provide the mobile subscriber with the data service as well as the voice service, the data rate has to be increased. In addition, as the data rate of the radio link is not stably guaranteed due to variation in the radio environment of the ratio link, the actual data rate may be lower than the specified data rate.
In the CDMA system, the base station and the mobile station exchange the call data (i.e., voice) using only one code channel (or traffic channel). However, it is not possible to transmit the greater amount of data efficiently and rapidly through one code channel that only has the data rate of 8.6 Kbps or 13.35 Kbps.
In summary, in the conventional data service system the base station and the mobile station exchange the data using only one code channel, which has a limited data rate, making it difficult to provide a high-speed data service.
It is, therefore, an object of the present invention to provide a method for allocating a plurality of code channels for the radio link between a base station and a mobile station to provide a high-speed data service.
It is another object of the present invention for controlling the code channels allocated for the radio link between a base station and a mobile station.
In accordance with the first aspect of the present invention, a method for operating supplemental code channels for a high-speed data service in a radio telecommunication system, comprising the steps of connecting a call between a mobile station and a base station; sending, by the mobile station, a number (NUM_SUPMS) and a hold duration (REV_DUR) of the supplemental code channels (SCC) to a base station controller through the base station to request the assignment of the supplemental code channels; upon the receipt of the request, sending, by the base station controller, the NUM_SUPMS to an SCC assignment processor (SCAP) of the base station to request the assignment of the supplemental code channels; upon the receipt of the request, assigning, by the SCAP, the supplemental code channels for the communication with the mobile station, and reporting the channel allocation result (ASS_SUP) to the base station controller; determining, by the base station controller, a number (NUM_SUP) and a hold duration (DUR) of the supplemental code channels to be assigned based on the channel assignment result (ASS_SUP); reporting, by the base station controller, the determined number (NUM_SUP) and the hold duration (DUR) of the supplemental code channels to the base station and the mobile station; and, operating, by the base station and the mobile station, the supplemental code channels based on the reported number (NUM_SUP) and the hold duration (DUR) of the supplemental code channels.
In accordance with the second aspect of the present invention, a method for operating the supplemental code channels for a high-speed data service in a radio telecommunication system, includes the steps of connecting a call between a mobile station and a base station; sending, by a base station controller for controlling the mobile station, a number (NUM_SUPBS) and a hold duration (FOR_DUR) of the supplemental code channels (SCC) to an SSC assignment processor (SCAP) of the base station to request the assignment of the supplemental code channels; upon receipt of the request, assigning, by the SCAP, the supplemental code channels for communication with the mobile station, and reporting the channel allocation result (ASS_SUP) to the base station controller; determining, by the base station controller, a number (NUM_SUP) and a hold duration (DUR) of the supplemental code channels to be assigned based on the channel assignment result (ASS_SUP); reporting, by the base station controller, the determined number (NUM_SUP) and the hold duration (DUR) of the supplemental code channels to the base station and the mobile station; and, operating, by the base station and the mobile station, the supplemental code channels based on the reported number (NUM_SUP) and the hold duration (DUR) of the supplemental code channels.
In accordance with a third aspect of the present invention, a method for operating the supplemental code channels for a high-speed data service in a radio telecommunication system includes the steps of connecting a call between a mobile station and a first base station, and operating a plurality of supplemental code channels; adding a second base station for a hand off to a radio link between the mobile station and the first base station; sending, by a base station controller controlling the first and the second base stations, a number (NUM_SUP1) and a hold duration (DUR1) of the supplemental code channels (SCC) to an SSC assignment processor (SCAP2) of the second base station to request the assignment of the supplemental code channels; upon receipt of the request, assigning, by the SCAP2, the supplemental code channels for the communication with the mobile station, and reporting the channel allocation result (ASS_SUP) to the base station controller; determining, by the base station controller, a number (NUM_SUP) and a hold duration (DUR) of the supplemental code channels to be assigned based on the channel assignment result (ASS_SUP); reporting, by the base station controller, the determined number (NUM_SUP) and the hold duration (DUR) of the supplemental code channels to the first base station, the second base stations, and the mobile station; and, allocating the supplemental code channels to the mobile station, the first base station, and the second base stations based on the reported number (NUM_SUP) and the hold duration (DUR) of the supplemental code channels.
In accordance with the fourth aspect of the present invention, a method for operating the supplemental code channels for a high-speed data service in a radio telecommunication system, comprising the steps of connecting a call between a mobile station and the first and the second base stations; requesting the assignment of the supplemental code channels (SCC) by the mobile station or a base station controller coupled to control the first and the second base stations; sending, by the base station controller, a number (NUM_SUP0) and a hold duration (DUR0) of the supplemental code channels to an SSC assignment processors of the first and the second base stations (SCAP1 and SCAP2), respectively, for assigning the supplemental code channels; upon receipt of the request, assigning, by the SCAP1 and the SCAP2, the respective supplemental code channels for the communication with the mobile station, and reporting the respective channel allocation results (ASS_SUP1 and ASS_SUP2) to the base station controller; determining, by the base station controller, a number (NUM_SUP) and a hold duration (DUR) of the supplemental code channels to be assigned depending on the channel assignment results ASS_SUP1 and ASS_SUP2; reporting, by the base station controller, the determined number NUM_SUP and the hold duration DUR of the supplemental code channels to the first base station, the second base station, and the mobile station; and, operating the number of supplemental code channels based on the reported number (NUM_SUP) and the hold duration (DUR) of the supplemental code channels among the first base station, the second base station, and the mobile station.